如何从wp_termmeta添加body_class

Question

I need to add body class from termmeta in woocommerce category This code did not work for me:

function lalka_custom_taxonomy_in_body_class( $classes ){
  if( is_singular() )
  {
    $custom_terms = get_term_meta($meta_id, 'custom-class', true );
    if ($custom_terms) {
      foreach ($custom_terms as $custom_term) {
        $classes[] = 'custom-tax-' . $custom_term->slug;
      }
    }
  }
  return $classes;
}

add_filter( 'body_class', 'lalka_custom_taxonomy_in_body_class' );

How can I do it?